Blind stitch sewing machines



Bec.V 18, 1956 E, FRANKLIN ETAL BLIND STITCH SEWING MACHINES Filed July 23, 1953 l lll( fg. Wfl( will s ll I9 FiG. i.

27 ze I8 8 \7 3| 24 ls I4 35 1 ,34 i lo 6 o .l 35 ,g S 7 9 Inventors FIG. 2.

United States Patent O BLIND STITCH SEWING MACHINES Edward Franklin,iAlwoodley, YLeeds, and Norman Adamson, Oakwood, Leeds, England This invention relates to blind stitch sewing machines and concerns lcertain improvements in the construction, mounting and operation of the head carrying and needle plate, needle, looper and feeder and their operating connections, and of the work support carrying the plunger or plungers.

Machines` of this type as heretofore constructedhave had the head Ysupported so as to be stationary during sewing, while the work support has been arranged to pivot relative to the head to allow insertion of the work between the two and to move the work up to the head, the work support being capable of limited movement to allow automatically for variations in thickness of material passing over it. v

Such a construction of machine has numerous disadvantages and drawbacks, some or all of which are overcome by the present invention.

In particular it is Yan object of the invention to eliminate the erraticplungering` motion Vcaused by undesired movement of the plunger or plungersy due to the effect on their operating connections of the pivotal movement of tlie worksupporte- A Y.. j

Another object is to reduce the amount of obstruction to the introduction and passage of the Work by enabling the area of the work support to be kept small as is required, for example, in sewing the lapel rolls.

A further object is to give easier access for the Work between support and head to facilitate correct positioning of the work relative to the needle and thereby minimise the risk of distortion and incorrect placing.

A still further object is to prevent the weight of the work from moving the work support and thereby causing erratic needle penetration due to incorrect movement of the plunger or plungers caused by the eiect on their operating connections of the pivotal movement of the work support.

Other objects are to cheapen and simplify the manufacture of the machines, to call for fewer working parts, and to enable better work to be produced or less skilled operators to be employed.

With these objects mainly in view the improved machine according to the invention has the head carrying the needle plate, needle, looper and feeder together with their operating connections arranged to be movable by the operator relative to the work support which is arranged to be stationary during normal operation of the machine.

The head and the mechanism it carries is pivoted on the machine body behind the work support so that when raised angularly the widest part of the gap for insertion and removal of the work is nearest to the operator.

In order that the invention may be clearly understood and readily carried into effectone construction of machine according thereto will hereafter be 'described with refsof erence to the accompanying drawings by way of example,

though the scope of the invention is not to be regarded as limited thereby. In these drawings Figure 1 is an end elevation of the main part of the machine looking in the direction of arrow A in Figure 2 but with certain por- 2,774,319 Patented Dec. 18, 1956 ice tions sectioned, whilst Figure 2 is a sectional elevation taken substantially on the line 11;]1 in Figure l.

Referring to these drawings the machine is shown .as having a base plate 1 which is secured on a table or support frame 2. The Work support is in the form of a hollow pillar 3 rigidly mounted on the base plate 1 near the front'thereof, that is nearest the operator, and its upper surface is of small area having'approximately the same dimensions for length and width.k The hollow pillar 3 containing one or more plungers 4 (two being illustrated) of usual construction which are pivoted therein and connected by links 5 to arms 6 secured on a rock shaft 7 supported below the base plate 1 and the body 8 of the machine. This shaft 7 can be rocked by links 9, 10 from an eccentric cam 11 driven through gears 12, 13 from a horizontal main shaft 14, this'arrangement being such that the plungers 4 are operated beneath the work in known fashion.

The main shaft 14 is supported at one end by a suitable bearing in the body 8 and has secured to it a belt pulley 15 through which it is driven from an electric motor (not shown). The other end of this main shaft 14 is supported by a bearing bushing 16 mounted in one end of a pivot sleeve 17 which is in turn supported for partial rotation in a long bearing formed by the body S.

This pivot sleeve 17 projects'beyond Vthe body 8 Vand has secured to it by screwed studs 18 the rear end of the head 19. This head 19 carries at its front end the needle plate 20, needle'21, looper 22 and feeder 23, all locatedv substantially VVabove the stationary work support pillar 3, together with the operating connections therefor in known fashion.Y

,One `end of the main shaftV 14 carries, rstly an eccentric cam 24 actuating'the linkr25 for the feeder 23, secondly an eccentric camY 26 actuating through 'a universal coupling 27 the needle bar driving shaft 28, and thirdly a universal bushing 29 actuating the looper shaft 3i), all in known fashion. By reason of these connections between the various head mechanisms and the main shaft and byV reason of the very small amount of angular movement of the rear end of the head caused by the lifting and lowering of the front end suiciently for insertion and removal of the work, there is no appreciable disturbancein the relative positions of needle plate, needle, looper and feeder.

The inner end of the pivot sleeve 17 has secured on it the boss 31 of an arm 32 which is connected by link 33 to a foot pedal (not shown). The sleeve 17 also has screwed into it a rod 34 whose lower end is acted on by the free end of a leaf spring 35 whose other end is anchored to the base plate 1, the pressure of the spring being adjustable. The arrangement is such that the head can be raised and lowered by the operator as required for insertion and removal of work the spring yielding horizontally to the angular movement of rod 34 and sleeve 17, and yet can lift against the spring pressure to allow automatically for Variations in the thickness of material passing beneath the head.

The sleeve 17 has secured thereon a further arm 36 the forked end of which engages ats on a long nonrotatable nut 37, this nut beingtlireaded on a vscrewed spindle 38 held against axial movement in a bearing 39 in the front of the machine body 8, the outer end of this spindle 38 having secured thereon a calibrated knob 40 for adjusting the position of nutv37 and thereby controlling the lowest position of the pivot head 19 and hence the depth of penetration of the needle. The abutment 37X formed by one end of the nut 37 limits the movement of the forked arm 36 in one direction and thereby limits the downward movement of the front end of the pivoted head.

By such a construction of machine many of the disadvantages of previous constructions are overcome. Morei over, theirigi'dly mounted ystationary work support ofY smll area enablesr for example, a lapel roll to'b sewn readily in a desired forrnwithout interference such as is K 1.7.Inablindrstitchtsewingmachnegethe combination of .aT stationary .,body', tiortion, a work support having `at .least one fplunger, said .Work'support,arrangedtobeastafV Y tionary Qdring, normaleoperationof .theY machnmll ,eloni 4.gatedhead.entending forwardly from saidrnachinebody .atfright angles;l thereto and .in af .direction parallel to the I line `ofrfe'ed :and-carrying at, itsiorward outer end ,aneedle j plate, 4neeclleglooper Y,andfeeder `andtheirLtoperatingicon- Y mations-said head having itsfrear..endpivotallymonnted on. ,saidmachine,body behind fsaid Vwork support. .so that w'hen its forwardoutertend js;-raised .angularlythel Widest part of: the gapV for ,i'nsertionandremolaloi ,the .Work is nearestito-the operator,;and.a manually operable means `connected to said pivotedfhead for-,enabling the Yoperatorio i ,lower. ,andraise the forward outer. end Qfsaid head with. its

l associated parts towards and awayfromr ,saidstationary ,SUPPOIt Vto allow insertion and removal ofttheiwrorkV 1 V,2.Ina blind ,stitch .sewing rmachine,. the.combination `as called forin claim ylrincluding AVain'iain drivingshaft, along pivotsleeve Vsupportedz'for.partial rotation in the machine. .body andA throughrwhich saidmaindr-iving shaft` for thestitchingmechanism .in the head; passes, said pivotY sleeve having secured theretotherear end ofY the head Y andconstituting the soletvsllPPOrtpor said head,` connecr`tionsirom said pivot` sleeve tolsaidV-manually'operable means by whichthe op'erator'can turn said sleeve ,tolr'aise t or lowerfthe forward louter end; of;said head,and 1an v.adjustable control device lc omprisinga member angularly Y Vmovable .with said Vpivot-vsleeveand an Vabutment supported fromv the Inachine Vbody arranged to cooperate with one another to .limit automatically ,to a Ypredetermined ,degree the. lowering of .the forward outerend of the head. during Vtheioperation .of the machine.- Y

Y* Y f :3. 'In'ablind V`stitchLsevvingmachine, (the combination of a stationary body portion, a work support having at least oneY plunger, said'work support Varranged tohe stationary during normal operation of the machine, a main' f driving shaft for the stitching mechanism, a long pivot sleeve and thereby lower and'raise the'V front end of said head with. its associated parts angularly in the'vertical Vvplane'` in which said, head,err-tendsand. .t0wa1dsl andgaway ,trol Adevice arranged v toglirnitV automatically. to a-gpredeterminedrwdegreett-he lowering Qfiheihead Ullng ith@ f .operation of the 1 machine, saidtfcontnol, dev-.ice inclu an arm secured on the pivot sleeve and-'havinglaiorkJ e end vengaging, ats lonfa. long nut non-rotatablythreadadfon i calibratedtknob, so as-tomove fsaidnu ainalgly, saidznnt t carryingvan abntmentloeatedsoas tonirnittheftmoyernent 1 of said arm in ,thetdirectiong corresponding to the llos/viteringA of the head.V

Referenee'srited in the'filerorffrthisr;patentY -iUNIrnnlsTArnsiPATeNIs- Vsaid Work supporga ,'footpedal connected to an arm on Y Y said piyot sleeve soas to enable the operator to turn said nl t 

